WO2015107618A1 - Method for manufacturing printed wiring board - Google Patents

Abstract

A method for manufacturing a printed wiring board comprises: a base formation step for forming a metal foil (12) as a base on a support plate (11); a mask formation step for coating a resist (13) on the metal foil (12) and patterning the resist (13) so as to form a resist mask (15); a conducting layer formation step for electroplating apertures (14) in the resist mask (15) so as to form conducting layers (16) which at least fill the apertures (14); an application step for applying an insulating base material (18) on the side on which the resist mask (15) and the conducting layers (16) are formed, in a state in which the resist mask (15) remains; and a removal step for removing the support plate (11).

Description

Method for manufacturing printed wiring board

The present invention relates to a method for manufacturing a printed wiring board using a transfer method.

As a method for forming a circuit pattern of a printed wiring board, a full additive method, a semi-additive method, and a transfer method have been conventionally known. The full additive method and the semi-additive method are methods of an additive method in which a circuit pattern of a printed wiring board is formed directly on an insulating substrate only by plating. The specific process of forming a circuit pattern by the full additive method is as follows. For a sheet in which a catalyst-containing sheet is pasted on an insulating resin, a pattern for plating (that is, a permanent resist) is used. A mask or a permanent mask is formed, and a circuit pattern is formed in a portion where the resist does not exist by electroless copper plating. On the other hand, the specific process of forming a circuit pattern by the semi-active method is a semi-active resist (removal) for a thin copper underlayer of several microns or less formed on an insulating resin. A resist pattern is formed by resist, and a circuit pattern is formed by electrolytic copper plating. Then, the resist is removed and the exposed underlayer is removed.

Also, the transfer method is a circuit pattern forming method in which a circuit pattern is formed on a support plate such as a stainless steel plate, and the circuit pattern is pressed and transferred to an insulating substrate different from the support plate. For example, Patent Document 1 discloses a transfer method in which a circuit pattern is embedded in an insulating base material to form a substrate in order to smooth the substrate surface.

JP-A-5-37157

However, in the above-mentioned full additive method, since the conductor which is a circuit pattern is formed by chemical copper plating, it takes time to deposit the conductor, so the processing cost increases and the manufacturing cost of the printed wiring board also increases. Become. Therefore, the above-described full additive method is not suitable for forming a relatively thick conductor, and is industrially applied to forming a relatively thin conductor.

Further, in the above-described semi-additive method and transfer method, it is necessary to remove the applied resist, so when forming a laminated board by laminating circuit patterns, the circuit pattern of each layer, which is a portion where the resist has been removed The space needs to be filled with an insulating resin or the like, which increases the manufacturing cost of the printed wiring board. Therefore, the semi-additive method and the transfer method described above are not suitable for forming a relatively thick conductor as in the above-described full additive method, and are industrially applied to forming a relatively thin conductor.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a printed wiring board manufacturing method capable of reducing costs even when circuit patterns having various thicknesses are formed. Is to provide.

In order to achieve the above object, the printed wiring board manufacturing method of the present invention includes a base forming step of forming a metal foil as a base on a support plate, a resist is applied on the metal foil, and a resist is formed by patterning. In a state in which a mask forming step of forming a mask, a conductive layer forming step of forming a conductive layer that fills at least the opening by applying electroplating to the opening of the resist mask, and the resist mask remaining, An attaching step of attaching an insulating base material to the formation surface side of the resist mask and the conductor layer; and a removing step of removing the support plate.

In the method for manufacturing a printed wiring board according to the present invention, the cost can be reduced even when circuit patterns having various thicknesses are formed.

It is sectional drawing in each manufacturing process of the manufacturing method of the printed wiring board which concerns on Example 1 of this invention. It is sectional drawing in each manufacturing process of the manufacturing method of the printed wiring board which concerns on Example 1 of this invention. It is sectional drawing in each manufacturing process of the manufacturing method of the printed wiring board which concerns on Example 1 of this invention. It is sectional drawing in each manufacturing process of the manufacturing method of the printed wiring board which concerns on Example 1 of this invention. It is sectional drawing in each manufacturing process of the manufacturing method of the printed wiring board which concerns on Example 1 of this invention. It is sectional drawing in each manufacturing process of the manufacturing method of the printed wiring board which concerns on Example 1 of this invention. It is sectional drawing in each manufacturing process of the manufacturing method of the printed wiring board which concerns on Example 2 of this invention. It is sectional drawing in each manufacturing process of the manufacturing method of the printed wiring board which concerns on Example 2 of this invention. It is sectional drawing in each manufacturing process of the manufacturing method of the printed wiring board which concerns on Example 2 of this invention. It is sectional drawing in each manufacturing process of the manufacturing method of the printed wiring board which concerns on Example 2 of this invention. It is sectional drawing in each manufacturing process of the manufacturing method of the printed wiring board which concerns on Example 2 of this invention. It is sectional drawing in each manufacturing process of the manufacturing method of the printed wiring board which concerns on Example 2 of this invention.

Hereinafter, embodiments of the present invention will be described in detail based on each example with reference to the drawings. In addition, this invention is not limited to the content demonstrated below, In the range which does not change the summary, it can change arbitrarily and can implement. In addition, the drawings used for describing each embodiment schematically show the printed wiring board and its constituent members according to the present invention, and are partially emphasized, enlarged, reduced, omitted, etc. to deepen understanding. In some cases, the printed circuit board and its constituent members are not accurately represented in scale, shape, or the like. Furthermore, the various numerical values used in each embodiment are merely examples, and can be variously changed as necessary.

<Example 1>
Below, the manufacturing method of the printed wiring board 10 which concerns on Example 1 of this invention is demonstrated in detail with reference to FIG. 1 thru | or FIG. Here, FIG. 1 to FIG. 6 are cross-sectional views in each manufacturing process of the manufacturing method of the printed wiring board 10 according to the present embodiment.

First, as shown in FIG. 1, a metal foil 12 serving as a base is formed on a prepared support plate 11 by an electroplating process, a chemical plating process, or other general film forming process (base forming step). Here, the support plate 11 is formed of a conductive stainless steel plate (SUS plate) or the like as a transfer substrate. Moreover, the metal foil 12 is plating used as the foundation | substrate of the conductor layer mentioned later, for example, electrolytic copper plating is performed about 12 micrometers.

Next, as shown in FIG. 2, a resist 13 is applied onto the metal foil 12, and the resist 13 at a predetermined position is removed by using an exposure developing device or the like (not shown), so that a desired opening 14 is formed. A resist mask 15 provided is formed (mask forming step). Here, a general resist resin material such as a dry film is used for the resist 13, and its layer thickness is about 10 μm. By forming such a resist mask 15, the metal foil 12 is exposed in the opening 14.

Next, as shown in FIG. 3, electroplating is performed on the opening 14 of the resist mask 15 to form a conductor layer 16 so as to fill at least the opening 14 (conductor layer forming step). In the present embodiment, as shown in FIG. 3, the conductor layer 16 is higher than the height of the resist mask 15 and the handle portion 16 a plated to the height of the resist mask 15 (that is, fills the opening 14). It is comprised from the umbrella part 16b which raised and plated (namely, it protruded from the opening part 14). That is, in the present embodiment, the conductor layer 16 that is the circuit pattern of the printed wiring board 10 is formed higher than the resist mask 15 in the cross-sectional view of FIG. (Layer thickness of the handle portion 16a and the umbrella portion 16b) is adjusted to about 100 μm. Further, as shown in FIG. 3, a part (outer edge portion) of the umbrella portion 16 b which is a portion formed higher than the resist mask 15 extends and protrudes from the surface of the resist mask 15. Such a portion on the surface of the resist mask 15 is an outgrowth 16c. In other words, the umbrella part 16b which is a part of the conductor layer 16 of the present embodiment includes the outgrowth 16c. Thus, when the umbrella part 16b of the conductor layer 16 includes the outgrowth 16c, the outgrowth 16c is used as a wiring independent of other parts (for example, the handle part 16a) constituting the conductor layer 16. be able to.

The conductive circuit board 17 composed of the support plate 11, the metal foil 12, the resist mask 15 (resist 13), and the conductor layer 16 is formed through the base formation process, the mask formation process, and the conductor layer formation process described above. . That is, in the conductive circuit board 17 of this embodiment, the resist mask 15 remains without being removed. In other words, in this embodiment, a permanent resist is used as the resist 13, and the resist mask 15 functions as a permanent mask (permanent mask) in the conductive circuit board 17.

Next, as shown in FIG. 4, two conductive circuit boards 17 and one insulating base material 18 such as a prepreg are prepared, and press-contacted so that the insulating base material 18 is sandwiched between the two conductive circuit boards 17. As a result, as shown in FIG. 5, the insulating base material 18 is attached to the formation surface side of the resist mask 15 and the conductor layer 16 (attaching step), and the two conductive circuit boards 17 and one insulating base material 18 are formed. A laminated body 19 is formed. In this embodiment, in order to form a double-sided board having a pattern formed on both sides of the printed wiring board 10, the two conductive circuit boards 17 are pressed so as to sandwich the insulating substrate 18, but the pattern is formed on one side. In the case of forming the formed single-sided plate, one conductive circuit board 17 and the insulating base material 18 may be pressed and bonded together.

In this embodiment, although the conductor layer 16 protrudes from the opening 14 of the resist mask 15, the resist mask 15 (resist 13) remains in the pasting process, so that the resist mask 15 remains. Compared with the case where it does not do, it becomes unnecessary to make the insulation base material 18 penetrate between the handle | pattern parts 16a of the conductor layer 16, and the quantity of the insulation base material 18 can be reduced. Thereby, the manufacturing cost of the printed wiring board 10 itself can be reduced.

Next, as shown in FIG. 6, the support plate 11 and the metal foil 12 are removed from the laminate 19 to expose the conductor layer 16 and the resist 13 (resist mask 15) (removal step). Thereby, the circuit pattern which consists of the conductor layer 16 is exposed on both surfaces, and formation of the printed wiring board 10 is completed.

As described above, in the method of manufacturing the printed wiring board 10 according to this example, in order to transfer the conductor layer 16 as a circuit pattern to the insulating base material 18 by the transfer method with the resist mask 15 remaining, Compared to the case where the resist mask 15 is removed, the insulating substrate 18 can be made thinner, and the manufacturing cost of the printed wiring board 10 can be easily reduced. And if the layer thickness of the conductor layer 16 becomes thick (for example, 100 micrometers or more), such an effect will be show | played more notably.

In addition, since the electroplating process is used instead of the chemical plating process for forming the conductor layer 16 in this embodiment, the conductor deposition time can be shortened. That is, the manufacturing cost of the printed wiring board 10 itself can be further reduced by the conductor layer forming step described above.

<Example 2>
Below, the manufacturing method of the printed wiring board 50 which concerns on Example 2 of this invention is demonstrated in detail with reference to FIG. 7 thru | or FIG. Here, FIGS. 7 to 12 are cross-sectional views in each manufacturing process of the method of manufacturing the printed wiring board 50 according to the present embodiment.

First, as shown in FIG. 7, a metal foil 52 serving as a base is formed on a prepared support plate 51 by an electroplating process, a chemical plating process, or other general film forming process (base forming step). Here, the support plate 51 is formed of a conductive SUS plate or the like as a transfer substrate, as in the first embodiment. Moreover, the metal foil 52 is plating used as the foundation | substrate of the conductor layer mentioned later, for example, electrolytic copper plating is performed about 12 micrometers.

Next, as shown in FIG. 8, a resist 53 is applied on the metal foil 52, and the resist 53 at a predetermined position is removed using an exposure developing device or the like (not shown) to form a desired opening 54. A resist mask 55 provided is formed (mask forming step). Here, as in the first embodiment, a general resist resin material such as a dry film is used for the resist 53, but its layer thickness is about 100 μm unlike the first embodiment. By forming such a resist mask 55, the metal foil 52 is exposed in the opening 54.

Next, as shown in FIG. 9, electroplating is performed on the opening 54 of the resist mask 55 to form a conductor layer 56 so as to fill the opening 54 (conductor layer forming step). In this embodiment, as shown in FIG. 9, the conductor layer 56 is formed only in the opening 54, and the layer thickness of the conductor layer 56 and the depth of the opening 54 (that is, the layer thickness of the resist mask 55). Are the same. That is, the conductor layer 56 is formed so that the conductor layer 56 and the resist mask 55 are flush with each other. In this embodiment, since the electroplating process is performed instead of the chemical plating process, the time for forming the conductor layer 56 (that is, conductor deposition) is reduced, and the manufacturing cost of the printed wiring board 50 itself can be reduced. .

A conductive circuit board 57 composed of the support plate 51, the metal foil 52, the resist mask 55 (resist 53), and the conductor layer 56 is formed through the above-described base formation process, mask formation process, and conductor layer formation process. . That is, also in the conductive circuit board 57 of the present embodiment, the resist mask 55 remains without being removed as in the first embodiment, a permanent resist is used as the resist 53, and the resist mask 55 is a permanent mask (permanent mask). ).

Next, as shown in FIG. 10, two conductive circuit boards 57 and an insulating base material 58 such as one prepreg are prepared, and press-contacted so that the insulating base material 58 is sandwiched between the two conductive circuit boards 57. As a result, as shown in FIG. 11, the insulating base material 58 is attached to the formation surface side of the resist mask 55 and the conductor layer 56 (attaching step), and the two conductive circuit boards 57 and the one insulating base material 58 are formed. A laminated body 59 is formed. As described in the first embodiment, when a single-sided plate having a pattern formed on one side is formed, one conductive circuit plate 57 and the insulating base material 58 may be pressed and bonded together.

In the present embodiment, since the resist mask 55 (resist 53) remains during the attaching step, the insulating base material 58 is formed between the conductor layers 56 compared to the case where the resist mask 55 does not remain. The amount of the insulating base material 58 can be reduced because there is no need to make it in between. Furthermore, in this embodiment, the conductor layer 56 does not protrude from the opening 54 of the resist mask 55, and the formation surface of the resist mask 55 and the conductor layer 56 of the conductive circuit board 57 is a flat surface having no unevenness. Therefore, it is not necessary to insert the insulating base material 58 between the umbrella portions 16b of the conductor layer 16 as in the first embodiment, and the amount of the insulating base material 58 can be further reduced. Thereby, the manufacturing cost of the printed wiring board 50 itself can be further reduced.

Next, as shown in FIG. 11, the support plate 51 is removed from the laminate 59 to expose the metal foil 52 (removal step). Thereafter, patterning is performed by known photolithography and etching so that the metal foil 52 has a desired shape, and the formation of the printed wiring board 50 on which a desired circuit pattern is formed is completed. By performing such processing on the metal foil 52, for example, a circuit pattern formed only from the metal foil 52 and a circuit pattern formed from the metal foil 52 and the conductor layer 56 are formed on the printed wiring board 50. Thus, a plurality of circuit patterns having different thicknesses can be easily formed on one substrate. Note that all of the metal foil 52 may be removed as in the first embodiment, and the removal process in the first embodiment may be the same as the removal process in the second embodiment.

As described above, also in the method for manufacturing the printed wiring board 50 according to the present embodiment, the conductor layer 56 as a circuit pattern is transferred to the insulating base material 58 by the transfer method with the resist mask 55 remaining. Compared with the case where the resist mask 55 is removed, the insulating substrate 58 can be made thinner, and the manufacturing cost of the printed wiring board 50 can be easily reduced. As in the first embodiment, when the thickness of the conductor layer 56 is increased (for example, 100 μm or more), such an effect is more remarkably exhibited.

Further, similarly to Example 1, since the electroplating process is used for forming the conductor layer 56 in this example, not the chemical plating process, the conductor deposition time can be shortened. That is, the manufacturing cost of the printed wiring board 50 itself can be further reduced by the conductor layer forming step in the present embodiment described above.

<Embodiment of the present invention>
A method for manufacturing a printed wiring board according to a first embodiment of the present invention includes: a base forming step of forming a metal foil as a base on a support plate; a resist mask on which a resist is applied and patterned on the metal foil; A mask forming step of forming a conductive layer, a conductive layer forming step of forming a conductive layer that fills at least the opening by electroplating the opening of the resist mask, and the resist mask remaining in the state, It has the sticking process which affixes an insulating base material to the formation surface side of a resist mask and the said conductor layer, and the removal process which removes the said support plate.

In the method for manufacturing a printed wiring board according to the first embodiment, in order to transfer a conductor layer as a circuit pattern to an insulating substrate with the resist mask remaining, the insulating substrate is filled between the conductor layers. Therefore, the manufacturing cost of the printed wiring board 50 can be easily reduced. Therefore, in the case of forming circuit patterns having various thicknesses including a circuit pattern having a relatively thick layer, the manufacturing cost can be reduced.

The method for manufacturing a printed wiring board according to the second embodiment of the present invention is a method for manufacturing a printed wiring board according to the first embodiment, wherein the thickness of the conductor layer is 100 μm or more in the conductor layer forming step. Thus, when a relatively thick conductor layer of 100 μm or more is formed, the effects according to the first embodiment described above are more remarkably exhibited.

A method for manufacturing a printed wiring board according to a third embodiment of the present invention is a method for manufacturing a printed wiring board according to the first embodiment or the second embodiment, and the metal foil is patterned in the removing step. Thus, by processing the metal foil, a plurality of circuit patterns having different thicknesses can be easily formed on one substrate.

A method for manufacturing a printed wiring board according to a fourth embodiment of the present invention is a method for manufacturing a printed wiring board according to any one of the first to third embodiments, wherein the resist mask is formed in the conductor layer forming step. The conductor layer is composed of a handle portion plated to a height and an umbrella portion having an outgrowth that is raised and plated higher than the height of the resist mask and a part of which protrudes from the surface of the resist mask. When such an outgrowth is formed, the outgrowth can be used as a wiring independent of other parts constituting the conductor layer.

A method for manufacturing a printed wiring board according to a fourth embodiment of the present invention is a method for manufacturing a printed wiring board according to any of the first to third embodiments, wherein in the conductor layer forming step, Electroplating is performed up to the height of the resist mask so that the resist mask is flush with the resist mask. By making the conductor layer and the resist mask flush with each other in this way, the surface in contact with the insulating base becomes a flat surface without unevenness, and it is not necessary to insert the insulating base between the conductor layers. The amount of material can be further reduced. Thereby, the further reduction of the manufacturing cost of printed wiring board itself can be aimed at.

DESCRIPTION OF SYMBOLS 10 Printed wiring board 11 Support board 12 Metal foil 13 Resist 14 Opening part 15 Resist mask 16 Conductor layer 16a Handle part 16b Umbrella part 16c Outgrowth 17 Conductive circuit board 18 Insulating base material 19 Laminated body 50 Printed wiring board 51 Support board 52 Metal Foil 53 Resist 54 Opening 55 Resist Mask 56 Conductor Layer 57 Conductive Circuit Board 58 Insulating Base Material 59 Laminate

Claims (5)

A base formation step of forming a metal foil as a base on the support plate;
A mask forming step of applying a resist on the metal foil and patterning to form a resist mask;
Conductive plating is performed on the opening of the resist mask, and a conductor layer forming step of forming a conductor layer that fills at least the opening; and
In the state where the resist mask remains, an attaching step of attaching an insulating base material to the formation surface side of the resist mask and the conductor layer;
And a removing step of removing the support plate. The method for producing a printed wiring board according to claim 1, wherein in the conductor layer forming step, the thickness of the conductor layer is 100 μm or more. The method for manufacturing a printed wiring board according to claim 1 or 2, wherein in the removing step, the metal foil is partially removed so as to pattern the metal foil. In the conductor layer forming step, a handle portion plated to the height of the resist mask, and an umbrella provided with an outgrowth that is raised and plated higher than the height of the resist mask, and a part of which protrudes from the surface of the resist mask. The method for manufacturing a printed wiring board according to any one of claims 1 to 3, wherein the conductor layer is configured from a portion. 4. The printed wiring according to claim 1, wherein, in the conductor layer forming step, electroplating is performed up to a height of the resist mask so that the conductor layer and the resist mask are flush with each other. A manufacturing method of a board.

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